关键词: 硫铝酸盐水泥;氢氧化钙;粉煤灰;强度;电阻率

Abstract: The influence of different contents of calcium hydroxide on the setting time , compressive strength and electrical resistivity of sulphoaluminate cement-fly ash composite cementitious materials were investigated .The results show that the setting time of cement paste was obviously shorten with the addition of calcium hydroxide .When the dosage of calcium hydroxide is 0 .5%, the setting time is the shortest , both the compressive strength at 1 d and 28 d are greatly enhanced .The compressive strength of cement paste at 28 d is 61.9%higher than the control when the dosage of calcium hydroxide is 2%.The electrical resistivity of cement pastes at 1 d decreases with the increase of calcium hydroxide .The maximum of the rate of electrical resistivity also decreases with the increase of calcium hydroxide , it indicates that calcium hydroxide accelerates the early hydration process of the sulphoaluminate cement paste blended with fly ash .The results from XRD analysis indicate that the amount of ettringite increases at 1 d with the addition of calcium hydroxide .At the age of 28 d, the amount of ettringite shows little change , but the compressive strength increases greatly , illustrates that fly ash contributes more to the development of strength .

Key words: sulphoaluminate cement;calcium hydroxide;fly ash;strength;electrical resistivity